Hydraulic testing machine



Dec. 7, 1943. G. R. EcKsTElN ETAL I HYDRAULIC TESTING MACHINE Filed oct. 27, 1942 Patented D'ec. 7, 1943 i 2,336,078 HYDRAULIC TESTING MACHINE George R. Eckstein and John P. Catlin,

port, Conn.,

Bridgeassignors to Remington Arms Cornpany, Inc., Bridgeport, Conn., a corporation of Delaware Application October 27, 1942, Serial No. 463,523

6 Claims.

This invention relates to material testing machines, and, more particularly, to an improved means for testing tubular articles.

An object of the invention is to provide improved hydraulic means for testing tubular articles. A further object is to determine the quality of cartridge cases by subjecting the case to a test under conditions simulating those prevailing in the chamber of a rearm when a cartridge is iired but without loading the test cases with powder and ball.

Other objects, features and advantages of the invention will be disclosed in the following speciilcation which is descriptive of one embodiment of the invention.

It will be understood, however, that the specific apparatus shown and described is for the purpose of illustration only and that the invention is not limited thereby but includes all embodiments and modifications falling within the scope ofthe appended claims.

In the drawing:

Fig. 1 is an elevation of the hydraulic testing apparatus of this invention.

Fig. 2 ls a plan view on line 2-2 of Fig. l.

Fig. 3 is a plan view of the weight latching means.

Fig. 4 is an enlarged fragmentary view, partially in section, of the housing used in the apparatus of Fig. 1.

Fig. 5 is a modification of the housing shown in Fig. 3.

Although the present invention relates to an improved means for testing tubular articles of any suitable material or configuration, the particular tubular articles chosen to illustrate the invention are metallic cartridge cases. It will be understood, however, that the apparatus may be adapted for testing tubular articles of other types.

The manufacture of small arms ammunition and ammunition components is an extremely spelcialized art embodying many exacting requirements of which one of the most severe is the problem of obtaining metallic cartridge cases and especially steel cartridge cases of substantially uniform quality.

As is generally known, a cartridge case is formed from a blank or disk of suitable metal by a series of cupping and drawing operations. suitable heat treatments being made between successive draws in order to soften the metal for additional working. After the iinal draw, the case has a substantially cylindrical body and a closed somewhat dome-shaped base, the latter lbeing squared up by subsequent operations known a`s pocketing and heading. Thereafter the base, now termed the head of the case, is finished in a head turning machine which trims the head to size and forms the extraction groove. The case is thus ready for necking which may be defined as an operation or operations designed to reduce the diameter of the open end of the case and to form the conventional shoulder and tapered body. It will be appreciated, however, that the case has been hardened by the last draw, and, consequently, it is necessary to anneal the upper portion of the case so as to soften the metal prior to the necking operations.

Moreover, this anneal, which is termed the body anneal. has an additional function in that it is designed to build into or contribute to the case those qualities which are essential to its successful performance in the chamber of a firearm. These qualities may be defined as a satisfactory proportioning within the body of the case of certain strength characteristics of the metal, namely yield strength and ductility so that the case may undergo the severe strains to which it is subjected on firing Without developing splits or causing cut-offs or other extraction diiiiculties.

It has been found that these qualities may be obtained -by controlling the extentof the anneal or more specifically by limiting the anneal to substantially the upper half of the case, the lower half will be found to have suicient hardness to obviate hard extractions while the upper half of the case will be soft enough to prevent cut-offs and splits.

The lower limit of the anneal thus becomes a measure of the proportioning of the hard and soft areas in the body of the case and is termed the line of anneal or .transformation line. By comparing the location of the transformation line on the body of the`test case with a standard measurement, an accurate indication will be had of the quality of the test case.

The present method of determining the quality of a case, and, in particular, an unnished annealed case by finding the line of transformation is extremely slow and painstaking. Briey, the test entails a microscopic examination of an etched section of a case to determine the approximate location of a line marking the beginning of crystalline growth in the metal, this line being` indicative of the extent of the anneal. At best, this method is tedious and one requiring the laborious preparation of specimens for examina- A second method of testing cases for proper quality has been to actually nre the loaded case Y components.

in a gun. Obviously, this test is not wholly satisfactory since the cases are tested long after`a considerable quantity have been nished and loaded. As a result, the test for the quality of the case is made not only extremely remote from the point at which quality was built into the case but also incurs a great waste of ammunition The present invention provides improved means for testing the quality of cartridge cases, namely by subjecting a iinished case to pressures simulating those in the chamber of a firearm but Without loading the case with. powder and ball.

Referring to the drawing, Figs. 1 to 5 show one form of apparatus designed and constructed for subjecting finished cartridge cases to pressure comparable to the pressures existing in the chamber of a firearm when a cartridge is fired.

In Fig. 1, the apparatus shown comprises a composite column indicated generally at 40 consisting of three posts 4| secured by suitable screw bolts 42 vertically on a disk shaped base 43 in substantially equally spaced relationship, as

shown in Fig. 2, the upper ends of the posts being similarly secured by screw bolts 44 to a head plate 45. A hardened steel block or anvil 46 is seated in a concentric recess 41 in the base block 43, the anvil being adapted to support a cartridge case housing which, as hereinafter described, is held substantially rigidly on the anvil by means of an adjustable yoke 48.

The yoke 48 comprises a substantially flat rectangular steel plate having a. U-shaped aperture 49 in one edge and is adapted to be supported symmetrically with respect to the vertical axis of the base 43 by a pair of posts 56 which are suitably secured to the base 43 on diametrically opposite sides of the anvil 46. The posts 50 project through suitably drilled holes 52 in opposite ends of the yoke 48 and are screw threaded at their upper end, as shown in Fig. 4, to accommodate nuts 53 for adjusting the height of the yoke with respect to the base.

Suitable means for transmitting a sudden blow to a liquid filled test case comprises a suitable weight 54 mounted to slide within the column defined by the three spaced vertical rods 4|, the latter constituting, in effect, means for guiding the weight. The latter is adapted to be raised by a suitable handle 55 which is shown threadedly secured at one end to the weight adjacent the upper end thereof.

Suitable means for latchingthe weight in its uppermost position, see Fig. 3, comprises a split block 56 having a pair of oppositely disposed semicircular apertures 51 in adjacent arms adapted to cooperatively embrace one of the guide posts 4| and to be drawn into rigid engagement therewith by a bolt 58 threadedly secured in the adjacent arms of the split block. A pin 59 projects laterally and upwardly at substantially forty-five degrees from the side of the block 56, thus providing a ilxed rest or hook for the handle 55.

The means for supporting a cartrid-ge case to be tested comprises a housing indicated generally at 66 consisting of two separable dies 62 and 63 encased within a holder 68.

The die or chamber 62 comprises a, heavy walled substantially cylindrical block having a tapered bore 64, the diameter and taper of which are critical. As explained above, this testing device is constructed and arranged to provide for the expansion of a finished and tapered cartridge case to substantially the same extent suffered by a loaded cartridge when fired in a chamber of a gun. To provide for this expansion, the measurements of the bore 64 of the chamber 62 simuchamber 62 has the maximum dimensions, in-

cluding head space, to which any case may be expected to expand when actually fired. Consequently, any test case which withstands the max-- imum expansion suffered in the test chamber 62 without developing splits or becoming permanently set, will have and will be indicative of those quality characteristics in similarly processed finished cases, which are necessary for satisfactory performance in the chamber of a rearm.

The member 63 comprises a heavy walled cylindrical shoulder die adapted to be superposed on the upper end of the die or chamber 62 in the manner shown in Fig. 4. The shoulder die has a tapered bore 65 at its lower end, the slope of which parallels that of the shoulder portion of a. nished cartridge case when mounted in the chamber 62 but which is spaced therefrom, as shown, to provide for maximum head space such as would be encountered in a worn gun chamber. Thus, when the test case expands in the dies 62 and 63, the shoulders as well as the body of the case, are tested for quality under conditions simulating actual firing conditions. The upper end of the tapered bore 65 of the shoulder die merges into a cylindrical bore or constriction 66, the diameter of which is substantially equal to the outside diameter of the mouth of the nished case, the function of the constriction 66 being to support and reinforce the walls of the mouth portion of the case and thereby prevent the untimely collapse of the mouth of the case. The constriction or bore 66 is reduced by means of a slightly tapered shoulder to form a cylindrical bore 61, the diameter of which is substantially equal to the inside diameter of the mouth of the case. The slightly taperedshoulder serves as an abutment for the upper end of the case while the' constricted bore 61 form a seal, with a plunger hereinafter described, for preventing the escape of liquid from the test case when it is subjected to high pressures.

The hollow cylindrical die holder 68 comprises suitable means for facilitating assembly of the separable dies 62 and 63 of the compound housing 66. The holder is provided with an open lower end 69 in order that the holder may be slipped down over the superposed dies and has a head portion 16. The latter is provided with a drilled hole 12 substantially in axial alignment with the holes of the assembled dies 62 and 63 and is of suilicient diameter to receive a flanged collar 13, the bore 14 of the latter being concentric with the drilled hole 12 of the holder 68. The diameter of the bore 14 is substantially equal to the diameter of the steam of a suitable plunger 15 and forms a bushing therefor, the plunger 15 being adapted to move down into the mouth of the test case and compress the liquid therein when struck by the freely falling weight 54.

In use, a nished cartridge case to be tested is filled with liquid and placed, as shown in the lower die or chamber 62 which is mounted on the anvil 46. The upper die 63 is then pressed down over the upstanding mouth and shoulder portions of the case, some force being necessary due to the relatively close fit between the mouth p portion of the case and the adjacent walls of the bore 66.

Thereafter the die holder 68 is slipped over the superposed dies and the entire assembly secured on the anvil by the yoke 48 which, is drawn down on top of the holder 68 by the nuts I3. The plunger being in position, the weight is then released and drops down onto the plunger striking it withvsuiiicient force to abruptly expand .the case within the housing into conformity withthe bores of the dies 82- and 63.

As a result, the test case is. swelled to the maximum size to which any case could expand in the chamber of a ilrearm. If, inremoving the case from the housing, the case does not stick but is readily removable by a normal pull of thel liquid filled tubular article; land an impact delivering means supported above said plunger and adapted to be released to strike said plunger with aforce of such magnitude as to develop hydraulic pressure sufficient to deform that portion of said article housedwithin the lower die.

2. Hydraulic: testing apparatus comprising a l base; a housing mountable on said base, said having axially aligned bores for supporting a liquid containing cartridge case with the mouth portion uppermost, the bore of the upper die having a constricted portion adapted to'coniine the of the order of five to seven pounds then cases ci the. same quality will not provide extraction diiiiculties. when actually loaded and ilred.

Moreover, if the test case is not split then it is not likely that cases similarly processed will develop cut-ois or ruptures when red in the der. and mouth portions, it will be clear -thatl other dies corresponding to the body and shoulder dies62 and 63 may be substituted therefor having bores of different size and shape to accommodate test cases at d`ifl.erent stages of processing. Forexample, in Fig. 5, is shown a modification of the apparatusof Fig. 4, wherein the housing indicated generally at-16 comprises the holder 68 and two separable dies 11 and 18 having axially aligned bores suitably shaped to receive a substantially cylindrical case such as one processed to have the body anneal referred to above. Since the open end of the cylindrical test case is of greater diameter than that of the mouth of a tapered test case, a plunger of larger diameter such as shown at 19 must be used to form a liquid seal with the w'alls of the open end oi.' thecylindrical case. By removing the bushing 13 from the drilled hole 12 in the head end oi.' the holder 68, see Fig. 4, a larger hole of the correct diameter is provided for the larger size plunger 19. The hydraulic test is made on the cylindrical case in substrike said plunger with a force of such maghistantially the manner described above and a del. Hydraulic ltesting apparatus comprising abase; a housing mounted on said base, said hous-y ing comprising separable dies having axially aligned bores for supporting a liquid containing tubular article with its open end uppermost, the bore of the upper die having a constriction for confining the upper end of the article, the bore of the lower die being of ygreater diameter than the diameter of the lower portion ofthe article, 'i

and a die holder for aligning said separable dies; a plunger adapted to be mounted in the bore of the upper die and movable therein into the mouth mouth of said case. -and a tapered portion dimensioned so as to be spaced from the shoulder oi said case, the bore of the lower die being of greater diameter than the diameter of the body portion of the case; a plunger adapted to be mounted in the bore oi the upper die and movable therein into the mouth of the liquid filled case;

and an impact delivering means supported above said plunger and adapted to be released to strike said plunger with a force of such magnitude as to develop hydraulicpressure sufficient to expand the shoulder and body portions only of the case in conformity with the upper and lower dies respectively.

3. Hydraulic testing apparatus comprising a base; a hou'sing mountablel on' said base, said housing comprising -two superposed separable dies'V having axially aligned bores for supporting a liquid containing cartridge case with the mouth portion uppermost. the bore of the upper die having'a constricted'portion adapted to conilne body portion of the case; a plinger'adapted to be mounted in the bore of the upper die and movy able therein into the mouth of the liquid filled case; and an impact delivering means supported above said plunger adapted to be released to tude as to develop vhydraulic pressure sufficient to deform the body portion of the case substantially in conformity with the bore of the lower die.

4. Hydraulic testing apparatus comprising a base having an anvil;-a slotted column mounted on said base comprising equally spaced substantially vertically vdisposed guide rods; a housing mountable within said column on said anvil, said housing comprising two superposed dies having axially aligned bores for supporting a. liquid containing cartridge case with its mouth portion uppermost, said bores being provided with a constriction for conning a limited portion of said case and an unconstricted portion to enable expansion of the unconiined portion of said case;.

a plunger adapted to be mounted in the bore of the upperl die and movable therein into the mouth of the liquid lilled case; means for delivering a sudden blow to said plunger comprising a freely falling weight constructed and arranged to be supported at the upper end of said column in axial alignment with vsaid plunger; anda handle on said weight elevating means adapted to be guided in one of the slots of said column.

-5. Hydraulic testing apparatus comprising a base having an anvil; a slotted column mounted on said base comprising equally spaced subst ntially vertically disposed guide rods; a ho g mountable within said column on said anvil, said housing comprising two superposed dies having axially aligned bores for supporting a liquid containing cartridge case withV its mouth pori-,ion uppermost: a plunger adapted to be mounted in the bore of the upper die and movable therein .into the mouth oi' the liquid lled case :means for delivering a sudden blow to 'said plunger comprising a freely falling weight constructed. and

arranged to be supported at the upper end of said column in axial alignment with said plunger;

, of the lower die.

two superposeddies having axially aligned bores, 15

the bore of the lower die being'shaped and having dimensions =substantially equal to 'those of the worn chamber of a iirearm when expanded to its maximum size by a forcev comparable to the force of explosion oi'r a cartridge-suitable for said chamber and of4 greater diameter than the diameter of the body portion of a standard cartridge case, the bore o tv the .upper die having. a

constriction adapted to confine the mouth of a case .supported within said housing; and hydraulic means for expanding the body portion of the liquid iilled case into conformity-with the bore GEORGE a. ECKSTEIN. JOHN P. camN. 

